Polyelectrolyte‐Enhanced Ultrafiltration for Copper Ion Removal from Industrial Wastewater

Abstract BACKGROUND Copper contamination in industrial effluents represents a significant environmental concern and restricts wastewater reuse. This study aims to evaluate the performance of polymer‐enhanced ultrafiltration (PEUF) for copper removal from industrial wastewater generated by a Tunisian cable manufacturing plant, using water‐soluble polyelectrolytes as complexing agents. RESULTS Three polyelectrolytes poly(acrylic acid) (PAA), poly(sodium 4‐styrenesulfonate) (PSS), and polyethylenimine (PEI) were investigated. Preliminary experiments using synthetic copper solutions assessed the effects of transmembrane pressure; pH, polymer concentration, and molecular weight on permeate flux and copper rejection. Conventional ultrafiltration showed poor copper retention (<13%), whereas PEUF significantly enhanced removal through the formation of polymer–metal complexes retained by the membrane. Under optimal conditions (3 bar, pH 7, and polymer concentration of 1000 ppm), copper rejection reached 96% with PEI and 95% with PSS, while PAA exhibited lower performance due to increased membrane fouling. When applied to real industrial wastewater, copper removal efficiencies of approximately 91% and 87% were achieved with PEI and PSS, respectively. Significant reductions in suspended solids, turbidity and conductivity were also observed, with moderate chemical oxygen demand removal. CONCLUSION The PEUF process demonstrates high efficiency for copper removal and enables compliance with the Tunisian discharge standard NT 106‐02. These results highlight PEUF as a promising and effective technique for industrial wastewater treatment and reuse. © 2026 Society of Chemical Industry (SCI).